The South Coast Air Quality Management District has issued a smoke and windblown dust advisory Thursday morning for those particular areas.

Air quality may reach the unhealthy range or worse to the Etiwanda Fire, which broke out Wednesday and has charred more than 1,000 acres. The gusty winds blew smoke across the western portion of San Bernardino County foothills and winds Thursday are causing elevated concentrations of fine particulates known as PM10 in affected areas.

The SCAQMD meteorologists predict strong Santa Ana winds to increase in the morning and continue through Thursday afternoon, bringing the possibility of increased smoke production from the fire.

Cities that may be affected by unhealthy air include: Rancho Cucamonga, Upland, Ontario, Chino, Chino Hills, Riverside, Norco and Corona. Cities in the Pomona/Walnut Valley including Diamond Bar, Walnut, Pomona, San Dimas, La Verne and Claremont may also experience unhealthy air quality levels.

But the highest concentrations of particle pollution is occurring in the Inland Empire.

Particle pollution can lead to increased emergency room visits, bronchitis and also, when particles are below 2.5 microns, can cause heart attacks and even premature deaths, according to the SCAQMD.